Experimental study on allografts of amniotic epithelial cells in calcaneal tendon lesions of sheep

An experimental protocol was designed to study the survival and behaviour of an allograft of amniotic epithelial cells (AECs) in an ovine model. The study was conducted on three healthy adult sheep. A core lesion was created in both calcaneal tendons under ultrasound (US) guidance by injecting 400 UI of Type 1A collagenase diluted in 0.6 ml saline. The AECs were obtained from a 60–80-day-old fetus and cultured under standard conditions. After 15 days of collagenase treatment, 2 × 10⁶ AECs stained with a vital membrane fluorescent probe (PHK26) were injected under US guidance in 500 μl saline solution into the lesion of one limb. The contralateral untreated limb was used as a control. Animals were euthanatized 7 (1) and 30 (2) days later. Histological analyses performed on explanted tendons clearly demonstrate that AECs survived for at least 1 month inside the lesion without any adverse reactions. The damaged tissue of the treated tendons showed a high number of reparative cells in active proliferation that were accumulating collagen within the extracellular matrix. In addition, after 1 month, the neo-collagen began to be organized into parallel arrays of fibers oriented along the longitudinal axis of the tendon.

     

Nuclear remodelling of in vitro grown sheep oocytes

Veterinary Research Communications -     

Factors affecting TRPV1 receptor immunolocalization in boar spermatozoa capacitated in vitro

Veterinary Research Communications -     

Effect of CB1 Receptors on Boar Sperm Plasma Membrane

Veterinary Research Communications - Pistilli, M.G., Bernabò, N., Gloria, A., Mattioli, M. and Barboni, B., 2007. Effect of CB1 receptors on boar sperm plasma membrane. Veterinary Research...     

Signalling Compartmentalization Involved in the Boar Sperm Acrosome Reaction

Veterinary Research Communications -     

Evidence for the presence of two bovine lentiviruses in the cattle population of Bali

Antibodies directed against two bovine lentiviruses, Jembrana disease virus (JDV) and bovine immunodeficiency virus (BIV), were detected in Balinese cattle sera using two new enzyme-linked immunosorbent assays (ELISAs) based on the combination of capsid (CA) protein and transmembrane (TM) peptides derived from JDV or BIV sequences.

Twenty eight of the 77 sera tested on the JDV ELISA showed anti-JDV antibodies with an unequal distribution of seropositive animals throughout the different districts of Bali. Furthermore, when 17 of the JDV positive sera were tested on Western blot, using the same JDV CA antigen, only 13 were judged positive confirming that the ELISA was a more sensitive technique for the detection of seropositive animals. Finally, 9 of the 49 JDV seronegative animals showed anti-BIV antibodies when tested on BIV-specific ELISA.

These two ELISAs appeared to be highly sensitive for the detection of anti-JDV and anti-BIV antibodies. Moreover, for the first time, animals showing antibodies against BIV were identified on the main island of Bali and on the JDV-free Nusa Penida island.     

Nerve growth factor production in sheep antral follicles

Despite their continuous turnover, sheep antral follicles are always regularly innervated. The local production of neurotrophins is probably involved in the control of ovarian innervation. In this context the present investigation was designed to evaluate the ability of sheep antral follicles to produce neurotrophic factors. In the first part of the paper neurotrophic activity was measured in follicular fluid of sheep antral follicles of different size. Using an in vitro model the effect of gonadotrophins on neurotrophin production was then evaluated. The levels of neurotrophic activity in conditioned medium or follicular fluid and the kind of neurotrophin produced were determined by using the chicken embryo dorsal root ganglia test combined with an immunoneutralization step. Follicular fluid from medium-large follicles (>4 mm) contains high levels of NGF (240-250 ng/ml), whereas the factor is nearly undetectable in small follicles (<3 mm) and in early atretic follicles. Experiments in vitro based on the culture of follicle shells for 12 hr confirmed that medium-large follicles can produce NGF. The production is strictly dependent on gonadotrophin stimulation. When gonadotrophins were not added or were added separately, no detectable levels of neurotrophic activity accumulated in medium. By contrast, in the presence of both LH and FSH the production of NGF became apparent showing a clear dose-response behavior. In addition, this production increased progressively with increasing follicle size from 4 to >5 mm up to values of about 60 ng/follicle, whereas follicles with a diameter of less than 3 mm were insensitive to gonadotrophins stimulation and did not produce significant amount of NGF. The data presented demonstrate that sheep follicles produce relevant amounts of NGF as long as the correct hormonal milieu is provided. Under these conditions the production of the NGF increases with increasing follicle size. This may be responsible for the rapid innervation of the wall of growing follicles and/or take part in other non-neural processes that are generally attributed to gonadotrophin stimulation.     

Oleoresin flow and chemical composition of Corsican pine (Pinus nigra subsp. laricio) in response to prescribed burnings

Oleoresin is an important defensive made up of acidic and neutral diterpenes together with a variable fraction of monoterpenes and sesquiterpenes. It plays a major role in plant-herbivore defense. Fire, or prescribed burning, can be a stress factor leading to metabolic changes in pine needles. Prescribed burning is used to: (i) restore fire to the ecosystem, (ii) recreate natural disturbance dynamics and (iii) reduce fuel loadings and fire risks. To our knowledge, no study has been performed on the effects of fire on the oleoresin defense system in pine trees, apart from the measurement of resin flow. We examined the effect on oleoresin production (resin flow) and the chemical composition (volatile and diterpene components) in Corsican pine (Pinus nigra subsp. laricio (Poir.) Maire var. corsicana (Loud.) Hyl.). This species is an ecologically and economically important pine in France. The chemical composition of samples was studied using HS-SPME GC and GC/MS for the volatile fraction and ¹³C NMR for diterpenes. A considerable increase in resin production and, consequently, an increase predominantly in diterpenes together with volatile compounds were observed at stations which had sustained recent prescribed burnings. Resin flow in trees in low-intensity prescribed burning after 4 years were no different than trees in unburned plots. Resin flow can be considered as a response to thermal stress. The major components of the two fractions were α-pinene (66.9–75.6%) and levopimaric acid (19.8–23.0%), respectively. The chemical composition of the resin remained unchanged after prescribed burning, even though resin production increased. No insect attacks were observed after low-intensity prescribed burning of P. laricio.     

Occurrence of Cu and Cr in the sedimentary humic substances and pore water from a typical sugar cane cultivation area in São Paulo,Brazil

Purpose

The purpose of this paper is to study the interactions of sedimentary humic substances (SHS) from a sugarcane cultivation area with Cu(II) and Cr(III) and to evaluate the occurrence of these metals in the pore water and SHS.

Materials and methods

For this study, the northwestern region of the State of São Paulo, Brazil, which is considered the region with the highest production of sugar cane in the state, was selected. Samples of sediment were collected from four sampling sites in the Preto, Turvo, and Grande rivers. The SHS and pore water were extracted from the sediment using the method suggested by the International Humic Substances Society and centrifugation, respectively. The complexing capacity (CC) of the SHS for Cu(II) and Cr(III) was determined by individually titrating these metals with an ultrafiltration system using tangential flow. The total concentrations of Cr and Cu were determined for the pore water, sediments, and humic substances with graphite furnace atomic absorption spectrometry and Zeeman background correction after an acid digestion, according to the methods described in US EPA Method 3050B.

Results and discussion

The SHS from a site in the Turvo River, which is typically cultivated with sugarcane, possessed the highest concentration of Cu bound to SHS (25.0%), the largest CC (0.63 mmol Cu g^?1 HS) and the highest concentration of this metal in the pore water (1.38 mg Cu Kg^?1 sed.). For Cr, the SHS collected from a location on the Preto River dam had the largest CC (0.90 mmol Cr g^?1 HS) and the lowest Cr content in the pore water (0.29 mg Cr Kg^?1 sed.), indicating that there was an inverse relationship between the CC and the concentration of metal available in the pore water.

Conclusions

Sedimentary humic substances might be one of the regulatory factors controlling the availability of Cu and Cr in the sediments found in a typical region that has been planted with sugarcane. Distinct behaviors were observed between the two elements investigated; higher CC and a larger fraction of Cu(II) were found in the pore water of samples originating from sugarcane crops. The opposite behavior was observed for the Cr(III) species.